Babbitt, Natalie. Review of The Grey King. The New York Times (September 28, 1975): 10. Babbit believes The Grey King to be the best of the series published up to that time. She praises Cooper's ability "to draw then and now to a plane where both exist with considerable fluidity."

Commire, Anne, ed. "Susan Cooper." In Something About the Author. Vol. 4.

Detroit: Gale Research, 1973. Written after The Dark Is Rising was published, this work cites Cooper's objectives in the series and gives a prospective on the books to follow.

Evory, Ann, ed. "Susan Cooper." In Contemporary Authors. Detroit: Gale Research, 1978. This is a biographical sketch, plus a list of writings, and provides some sidelights on the nature of Cooper's writings.

Levin, Betty. "A Journey Through Mountain and Mist: The Grey King." Horn Book (August 1976): 443-445. This review explains how in The Grey King "each event .. . is colored...